Method of and apparatus for dring refractory materials



Jan. 26 ,1926. 1,570,659

' W. E` WILSON ET AL METHOD OF AND APPARATUS FOR DRYING REFRACTRYMATERIALS Filed Dec. 11, 1923 B SheetsSheet 1 TT nml] alf 4 A l UL v 35/Jan. 26 1926.

w. E. WILSON ET AL METHOD 0F Arm APPARATUS Fon DRHNG nEFRAc'ronfMATERIALS Merz,

Jan. ze ,1926. 1,576,659

W. E. WILSON ET AL METHOD OF' AND APPARATUS FOR DRYING REFRACTDRYMATERIMJ Filed Dec. 11, 1923 8 Sheets-Sheet 5 Jan. 26 1926. 1,570,659

W. E* WILSON ET AL 10u-:Tann or' AND APPARATUS Foa DRYING Vman-mlm'rolwFiled Dec. 11, 1923 MATERIALS Sheets-Sheet 4 Jan. 26 1926. 1,570,659

w. E. wxLsoN Er AL METHOD 0F AND APPARATUS FOR DRYING REFRAGTORYMATERIALS Jan. 26 1926. Y .,5`F,659

w. E. wiLsoN er Al.

METHOD F AND APPARATUS FOR DRYIN REFRACTORY TERIALS Filed Dec. 11, 1923e Qheats-Sheet 6 5 Inuemof:

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Vm 05ML www 'Jain 26 1926.

W. E. WILSON AL METHGD 0F' AND APXARATUS FOR DRYING REFRACTQRY MATERIALSFiled Da. 11, 1923 Jan. 26 1926. 1,570,659

w.`E. wlLsN Erm. METHOD F AND APIARATUS FOR DRYING REFMGTORY MATERIALSFiled nec, 11, 192s a sheets-sheet Patented Jan. 26, 1926.

UNITED STATES PATENT OFFICE.

WILLIAM E. WILSON, OF MASON CITY, IOWA, AND HENRY G. LYKKEN, OF MINNE-APOLIS, MINNESOTA.

METHOD OF AND, APPARATUS FOB. DRYING BEFRACTOBY MATERIALS.

Application tiled December l1, 1923. Serial Ro. 679,954.

To a!! irlioui it may concer/t.'

lle it known that we, lViLLLiM E. l'VlLsoN :ind HENRY (il. Li'KiiisN,citizens of the United States, residing, respectively, at Mason City,Iowa, and Minneapolis, Minnesota` have invented certain new and usefulIniproveinents in Methods of and Apparatus for Drying RefractoryMaterials, of which the following is a specification.

The present invention relates to the drying of refractory materials andwares, such as refracto'ries, bricks, tiles, hollow tiles, floor tiles,building tiles, wall tiles, drain tiles, sewer pipes, products roduccdby the clay and like industry, moliied or model wares,

ott/ery, porcelain, ceramic wares, rough c ay Waies, terra cotta,plastic and dry pressed material, and all other various and similararticles and substances, by the use of heat and mechanism or apparatusfor effecting such drying.

Among the objects of the invention are to dry refractory materials in avel' short period of time wthout danger of tie sur` face of the materialcracking or checking, long periods of time together with a slow orgradual change in temperature heretofore having Ibeen required to avoidthe objection of cracking 4or checking; to rapidly absorb and cause arapid evaporation of the moisture within and on the surface of thematerials or Wares Without the previously required exercise of the greatcare to prevent a rapid absorption and evaporation which heretoforecaused checking; to heat the materials in an atmosphere or surroundingmass of fluids or gases saturated or nearly saturated with a vapor, suchas water vapor, preferably in the form of steam, to a ten'iperatureslightly in excess of the boil ing point of water, if water vapor beused; to almost or substantially balance or equalize the vapor tensionut the surface of the niaterzils so that in the interior ofthe materialsiu order that when the temperature is raised, flic transfer of theinternal moisture in the iiiatcriiils will be substantially equal to tuerate of evaporation of the moisture upon the exterior surface of thematerials, thereby preventing case-hardening of the surface und crackingor checking by reason of internal steam pressure or other stressesheretofore occurring; to cause the internal moisture to rapidly leave orpass to the exterior to provide means for su surface of the materials,under its own vapor tension as the temperature rises, the physicalconditioin of the surface of the Wares being maintained similar to thatof the interior in so far as moisture content ma be concerned, by thecontrol of the condition of the surrounding or enveloping fluid mediumor gases; to greatly reduce the time required for dryin and to obtainthe objects above noted, gy the subjecting of the materials to anenveloping mass or atmosphere of superheated steam; to carry out theabove by a method of subjecting the materials, preferably in passages ortunnels of a drying kiln, or the like, whereby the materials arepreferably caused to move or travel progressively, to heat in excess ofthe temperature of the boiling point of Water in a controlled humidilledmass or volume of fluids or gases, which ma be the hot products ofcombustion or tie waste gases of furnaces or the like, means being usedto control the amount and the temperature. thereof and also the qualityof the humidit or the relative humidity, such that the iluids' willabsorb the surface moisture at substantially the same rate as that ofthe transfer of the internal moisture to the surface of the materials;to provide novel means and apparatus for accomplishing these objects; toprovide means for circulatin preferabty at different points of the traveof the mterials, heated and humidied fluids or gases through and aroundthe materials or wares; pplying, preferably at different points oftravel of the matierials, humidifying vapors, such as watei spray orsteam, or the like; to provide means for regulating, independently ateach point, the quantity of humidifying matter; to provide means forrecirculating part of the heated and humidied fluids with the heatedfluids being circulated by the circulating means; to provide means forreguling, at different points, the amount of fluids to be recirculated`thus regulating or controlling the temperature and humidity of thefluids acting upon the wares or materials in the different parts oftheir travel through the kiln: and such other objects, advantages andcapabilities as will later more fully appear und are inherentlypossessed by the invention.

In the accompanying drawings illustraf of a modification;

ion line ing a preferred' formfof kiln for carrying out the hereindescribed process or method; I"ig. 1 is a horizontal Sectionalvviewtaken on su -a-ntially the floor level of the kiln; Fig. 2 is alongitudinal sectional v iew taken 2 2 of Fig. l1 of the drawings;vlfig. 3 is a, `vel-'tical' A'lol'igtudi'al1-sectionsl .view takenV "nline 3;-.3of 1 ofthe drawings Fig. Pis a verticallongitudinnl sectionaview taken 011 lille 4 4 of- Figi lof the drawings; Fi 5 is a top-planview of the kiln and operatin inecV y for operating parts thereof; -,isa horlzo'nt'a'l sectional view showing the `upper portion of the kiln,partlyin pian and partly in section; Fi 7 is a transverse sectionallview taken'enine 7 of Fig. 1 of the drawings; F ig. 8 is a similar viewtaken on the line 8 8 of Fig. 1';- Fig`. 9`i's a similar view taken online'--Q of'Fi 1; Fig. 10 is a broken horizontal sectionalr view,similar to Fig. 1, VFig. 11 is a tranwerse sectional view ofthe same;andFig. 12 is a similarvview of a further'modication.

Referring now more particularly to the drawings uponv which isshown anillustrative embodimentl of means, preferably in the form of a tunnelkiln, for carrying out the method herein dsclos'ed, the wares ormaterials 1. are loo ely packed upon cars 2 running'overitraclsZ-l and 4through a numberof passages o'rtunnels 5, 6, 7 and 8, it beingunderstood that the number of passages and tunnels is merely aV matterof chice, asa lesser,l or larger number than that shown; upon thedrawings may be used. Tlife cars 2 'are preferabiy made to progressthrough eachtumiel` over the tracks 3 and 4 hy any suit-able means, suchas a.V motor driven chain device l) located in each ante chamber 10 andcapable of engaging with the cars entering thev ante chambers 1wherebythe chain device causes a movement of the cars, and hence the train ofcars ahead, so that the train will eventually pass or prot ie cars willpass tothe exterior of the kiln atteitlie wares or materials carriedthereby, have been treated. The ends nuls may bc closed, as desired, bydoors 11 and 12, and suitable doors 13 may also hu used between the antechambers 10 and the tunnels.

Beneath the tunnels of the kiln, aud near the ends thereof, are providedinlet and out- 4vertical wall 21.

*Figa longitudinally.'

Va;msm-cliroli having aand Ill; respectively i of the tun.' 'interiorof' luuiu'lsy f1 exhaustside of n furnace or the like, or the conveyingof heated air or gases receiving their heat from the waste heat offurnaces, oij the drawing ofhot flue or stack gases and the like fromthe exhaust side of furnaces, as may be desired and found conven. ientto do; The outlets of cross conduit l5 may be connected at either orboth ends to an exhaust device, which may have a blower and a stackcapable of producing the re quired draft to draw the heated fluidsthrough the kiln.

he cross duct 14 has .i number of dis- 'l ports 16 communicating withthe after having pei-formed their functions. mayy be exhausted throughthe ports 15 into the duct 15 and carried away to the stack.

The duct 1 l also communicates, hy way of u lateral port. withlongitudinal and cen' which is pref ti'zilly loculed ,uns chamber l0@rahly located l:' wenn the two halves of the chamber, as clearly shownin Fig. lof the drawing. This chamber has a coverin or roof 20 und isclosed at its other' end li'y a At intervals along sides of the roof 20are provided and 9.3 controlled h v suitable gates crs 24 und 25 wnichmay be operated by pug chains 2G and Qpcapnlile of adjustment annoperation from lho operating room 28 ifi;- cated above the kiln, asclearly shown in 7 oflludrawings'. liinsvursolv licnculli the tunnels atinten are provided passages 25), 30, 3l and 32 outlet ports 33, 34, 35ouununicatin.r with the und 4. The inlet ends of post-i of tht-s1,-pussngcs are respectively controlled liv slidingr gates or dempers 37:lud HS :rtulily connected to bars 3D and 40 which muy his operated fromthe o erating room 28, :is-1 che-urli' shown in Fig. of thcI drawings.It will he noted that the ports 22 und 23 in the roof 2Q are so locatedthat they have easy communication with thc adjacent pair of inlet portsto the passages 30 and 32. and 29 and 31 respectively, as clearly shownin Fig. l of the drawingsy Above the tunnels is provided a llooringhaving a plurality of outlet :pcuings or ports 4l and 42 for the upwardpassage of the hot gases und vapors as tlicv leave the ports 22 or damii wardly as municate laterally' with "so that humidity nels with ports47V Va try of gases -from-i 'explained mord uliy hereinafter.

treated, sverali" moisture parts of the kiln.

ports in the flooring of l' "upper chambers 43, 44, 45 and 46 :hay alsobe materials 1 on the cars, and pass illtdthe provided at inte i als andto extend downupper chambers 43, 44, 45 and 4:6 eaitendig longitudinallyabove each tgnnpl fcmh municating at the ent n ,A flow of gases to the ithe cross duct l b .way of, he.

Y. .IM-u By referring to it will be lzilnjdepe that the ports 41'ad 4t2form esorto# checker work in thev floor' ,whereh the. gases may Ipasseasily upwhil and nereinaiter more fn 'also 0 nal chamber 49 l ber 19'and spaced' of s Vra c l the gans 52 in t e mixing chamber 50.

(1Q suppl e chamber 49 and capable or moisture just-beneath See It is'to be understood that ying moisture may be sulpani point desiredthroughout t e ncng upon the convenience und the articular amount ofmoisture to be sup- Each of these spraying devices are {suitablycontrolled in any desired manner so that the amountof moisture .can bevaried waz-diy through ying Sie as desired at the various points in thekiln,

Referring more particularly to Figs. 1U,

,11 and 12. `the construction ofthe kiln is substantially the same asheretofore described with the exception that an additionalconduit 60 isprovided between the cham- ;berfs 19 and 50. It has been found that ifchamber is mme -a.;15gg; m.Emmier a longitudinaliqggas nglettoriheingsepanl b were if @vinde-e arals; rotti?, im?? aiitbly drivenhypo-vier coated 1n thepper ating room` `28 as clerlyfshown i7 and 9the- A ...il u her 50 is located immediately ahoy 4c roof 20, thelatterv being Vso sha edgthatthemixing chambenO with the crosspassagesf29,.30' well as with the chamber 19 by' way of the ports 22 and23, as' clearly. shown in Fig. 7 of the drawings. The fa-a 52? mjay beYrotated in either direction to cause"acirculation of the hot gasesandvapors through the mixing chamber 50 and through the cross passages,then through the "tunnels, then through the upper i chambers and backagain into the. 7 ing chambers. This circulation iscarriixon togetherwith the entliexzliamber 19 as'will be In order thatrthe.- hot gasesor'uids supplied to Vthe f'JclQln smily have the' proper amount ofhmiditfhr moisture when the same reaches the'wares or materials to be suplying or spraying means .may be prori de In the ridge portion of therooff is provided a spray pi ne 53 which peferablycxtends longitudinallyof O andxs. ca ableV of spraying water into the ciiamber to supply auantity-of. moisture to 4the hot ated therethrough. In the tuntween thetracks, may also be ovided similar spray means 54 and 55 as'c earlyshown in Fig. 7 of the drawing,

muy be'supplied to the in- -coming gases passing upwardly through thethe tunnels. In the orgte products of combustion we into direct contactvwith ploducts would have chemicals, such as sul- .phtgr' and the like,which might have au efect of producing a coloration of the wares 'whichwould not be desirable. In order that the heat of the products of`combustion may be utilized and the chemical action upon the waresavoided. the kiln may be constructed with the additional conduit 6()'which has no communication with the passages of the kiln whereby any ofthe gases passing therethrough could have access to the wares, but thisconduit is so located that it will conduct gases therethrough from itsinlet end 61 to its outlet end 62 where it will discharge into theexhaust or outlet cross any convenient manner as clear' 1y shown in Fig.10 of the drawin In-v asinuch as these gases are usuallyo highertemperature than the otherV gases,-the heat of radiation obtainedtheregonr through thewalls of the conduit may be obsorbed and utilized.ing of the heat, the conduit 60 i provided with a plurality of rangedand dis path of the stre-.un of gases circulated by the funs 52. `Theconduit 60iis'so located with reference to chambers 19 and 50'that theyvwill give heut to both the gases in the ehamA ber 19 and to the'gascsand vapors in the chamber 50. Fig. 11 shows one form of thisconstruction, and` Fig. "l2 is a similar form where the main supply ofgasesv is `from the upper part of the central chamber instead of frombelow. In the form shown in Fig. 12 the operating shaft of the fans 52,may if desired, extend the conduit 60 without any material leakage ofgases Lem the conduit. In odperation the hot gases pass into the crossuct 14 and a small portion of these gases pass upwardly through theports 1n 'into the tunnels, the amount thuspassing up being controlledby-thedempers 17. The main portion of the gas passes into re to bebrought the wares, such S preferably ns,63 so ar- In order to help theradiat- '4 110 posedthat they will be in the" .hilly l I 1 5 gases andvapors 1n the direction shown by 16 wa rdly gases and moisture and 20Shown in Fig.

the ports 15 and shown in Figs. 10, l1

55 sage 19.

J uhcre it heals the root' 2H for giring radiated heat to the tiuids inthc mixing chamber 5U. The fans'52 be thrown into operation to'circulate thc central chamber the arrows, but it is to be understoodthat the circulation -may be in the reverse' direction it desired The.sliding gates 3? and 38 may lzc regulated as desired tocontrol the 10circulation of the gases through the passages 29,-.l0. 3l and 32.Assuming that the dempers Q4 and 25 are closed, it will be noted thatthe hot. gases first enterinto the tunnels through the ports 1G and passupl into the upper chambers 43,44, from whence the fans draw the intothe mixing chamber to be recirculated again through the cross passagesin the tunnels, as clearly 7. lt will be noted that the movement of thegases is in a sort of a spiral or helix in each side otl the kiln, thegases progressing toward the other end of the kiln where tley arefinally exhausted through into the cross duct 15l are passing throughthe 50 they are increased in and 46 While the gases mixing chambertemperature by the radiating heat given ott by the root 20, or m theform of device and l2, the radiating heat giren ofi' by the surface otthe conduit 60, in addition to that which may he given oli' by the roofportion l0 connected between the conduit and the side walls ot If it hedesired to add to the gas circulation, the dampers 24 and 25 may (hen beopened and regulated to the desired amount. to receive or bleed inadditional amount of hot gases. ln this way the amount of gases may heregulated withrefcrence to the amount of n'loisture supplied thereto sothat the relative humidity of the gases is such that the transfer ofmoisture from the surface of the wares or materials in the tunnels willlle substantially thc same or slightly greater than the transfer ofmoisture trom the interior of the ware so that there ,will notbe acracking orchecking of the surface of the ware by the too rapid transferof moisture from the interior thereof to the exterior.

lhile we have herein shown one direction of circulation by arrows inFig. 7 of the drawing. it is to he understomi that the inventioncomprehends the circulation of gases iu either direction as desired anddepending upon the convenience of operating the kiln. rl`his is alsotrue as to the, forms shown in Figs. 10, l1 and 12.

The various parts of the device may be operated from an operating roomlocated a ove the furnace and includintY suitable power operatingmachinery tor carrying out the desired result. Such machinery murvcomprise a motor belted -to a shaft 65 the paswhich in turn is connectedto the fans by tells (5 (5 and also by belts (i7 to a mechanism for oerating the chain device 9 in the ante cham ers of the =kiln.

As the mixture off gases and vapors pass toward the end of the kiln theypass downwardly through the ports-'15* and into 'the cross'duct 15 andthen :e to an exhaust device or stack whereby they pass off tothe at-vmosphere. It will'thus'be seen that as the wares or materials enter thetunnels, they first come into contact with a mixture of heated gases andvapors highly charged with moisture but lower in temperature than thewares will belater subjected to as they progress through they tunnels.Upon leaving the tunnels and Vafter all of the moisturel has beenextracted from` the Wares, the wares are now subjected to a dry hotfluid for completion of evaporation of all moisture from the' wares sothat the wares are discharged from'the kiln in dry state.

iVhile we have herein described and shown upon the drawings a fewembodi-V ments of the invention, it is to be understood that theinvention is not limited to the arv ticular arrangement of parts,details and constructions described and shown. but that it alsoeomprehends other arrangements of parts, constructions, and details,without departing'from the spirit lof the invention.

Having thus described our invention, we claim l. method of dryingrefractory Ware, comprising moving the ware through a heatingr andhumidifying medium, the ware being subjected to increasing temperaturesund decreasing hnmidities during said movement ofvfithe Ware throughsaid medium, causing a general travel of said medium in a directionopposite to the travel of the ware, and forcing;r said medium atsuccessive points vertically through said ware.

method of dryingr refractory ware, comprising moving the ware through aheating and humidi'fying medium, the ware being subjected toincreasingtemperatures and decreasing lm|nid-itiesduring said movementof the ware through said medium. forcing a portion of Said med-.nun in adirection opposite to that of the" movement of the ware, forcing anothero'ition of the me` dium vertically throng said ware, and feedingregulated amounts of said medium from said first mentioned portion tosaid second mentioned portion.

3. A method of drying refractory ware, comprising moving the warethrough a heating and humidifying medium, the ware being subjected toincreasing temperatures and decreasing humidities during said movementof the ware through said medium, forcing a portion of saidmedium in adirection.opo posits to that of the inovement of the forcing anotherportion of the medium iso tically through said ware, and lfeedingregulated amounts of said medium from said first mentioned portion tosaid second menware to and t tioned portion, and subjecting said first'poi-- tion to radiant heat.

4. A method of drying refractory ware, comprising movin the ware througha tun nel of a kiln or t e like, forcing a heating medium through apassage in said kiln in a direction opposite to the direction ofmovement of the ware in the kiln, diverting regulated portions of saidmedium from said passage at successive points into and through said wareat successive points thereof.

5. A method of drying .refractory ware, comprising movin the warethrough a tun nel of a kiln or tie like, forcing a heating mediumthrough a passage in said kiln iii a direction opposite to the direction.of move- ,ment of the ware in the kiln, diverting reg nlated portionsof said medium from said passage at successive points into and throughsaid ware at successive points thereof, leading the diverted amounts ofsaid medium to points where humidity may be applied, and supplyingregulated amounts of humidity to said diverted amounts of said medium.

6. A ,ethod of drying refractory Ware, comprising movin the ware througha tunnel of a kiln or t e like, forcing a heating medium through apassage in said kiln in a direction opposite to the direction ofmovement of the ware in the kiln, diverting regulated portions of saidmedium from said passage at successive points into and through said wareat successive points thereof, and leading each of said diverted amountsof said medium after passing through a point of the the ware and in the'same direction through said ware as it previously passed through theprevious point of said ware.

7. A kiln for drying wares, comprising a tunnel for the passage thereinof the Ware to be treated, a gas chamber extending along the side of thetunnel, a mixing chamber extending along the side of the gas chamber,and admission chambers located above ,and below the tunnel, saidadmission chambers having series of ports located for the passage of hotgases from the gas chambento t e mixing and admission chambers andthrough the ware in the tunnel.

8. A kiln comprising a passage for the movement of ware therethrou h,admission chambers above and below sai passage and having ports ofcommunications between said assage and said admission chaml ers,a mixingchamber having ports of communication with said admission chambers, andmeans for conducting a treating medium with said mixin chamber.

9. E kiln comprising a passage for the movement of ware therethrough,admission chambers above and below said passage and rough a succeedingpoint of g having ports of communications between said passa e and saidadmission chambers, a mixing c ian'iber having ports of communisationwith said admission chambers, means`4-` for regulating the size of saidports at will, 7 and means for conducting a treating medium into saidmixing chamber.

y10. A kiln comprisinga passage for the movement of ware therethrough,admission chambers abovie and below said passage and '(6 havingports ofcommunication between said passage and said admission chambers, u mixingchamber having ports of communication with said admissimchamhers, a ductbelow said mixing chamber, vsaid duct liiivinga p liiralit of portscommunicating with said mixing c amber at diereiit points, and ieansAfor conducting hot gases into said uct.

movement Vof ware therethrough, admission chambers above and below saidpassage and having ports of communication between said assage and saidadmission chambers, a mixing chamber having ports of communication 0moving the materials, means for conducting lo heated gases to saidpassages, means for 'circulating the gases through the materials, andmeans for withdrawing the circulated ases.

ing refractory material along' said tunnels,h gas'inlets andloutlets insaid tunnels, means controlling the flow of gasinto the tunnels,

and means for 'recirculating part of the gases no means controlling theflow of gas into the 12 tunnels, and means located at intervals in saidtunnels for forcing moisture into said gas circulated through saidtunnels.

16. A kiln having tunnels, means for moving refractory material alongsaid-tun- F nels, gas inlets and outlets in said tunnels, meanscontrolling the `flow of gas into the tunnels, and means locatedadjacent the inlets of said tunnels for suppl ing water vapor to the gasflowing into sai tunnels.

11. A kiln comprising a'passage for the 35 rts, and.meaii's for i 1 3. Akiln having tunnels,.means fonmov 105 s for supplying hu- 115 17. A kilnhaving tunnels, means for moving refractory materials along said tunsnels, gas inlets and outlets in said tunnels,l

means controlling the flow of gas into the tunnels, means locatedadjacent the inlets for supplying water vapor to the 'gas flowing intosaid tunnels, and means for re lating the amount of `vater vaporsupplied at each of said inlets..

18. A drying kiln for refractory materials, passages for the materials,means for moving the materials through said passages, means 'Forcirculating heated and humidified gases through the materials in thepassages, and means for iccirculating part of the cii'- cul-ated gaseswith the incoming gases at successive points beyond the previous pointsof circulation of the gases.

19. A drying kiln for refractoryr materials, tunnels, mea ns for movingthe materials through the tunnels, means for heating the materials abovethev boiling point of water, means for supplying at successive points insaid tunnel moisture to the exterior surface of the materials at a ratesubstantially equal to the rate of evaporation on the surface of thematerials.

20. A drying kiln for refractory mate rials, a tunnel, means for movingthe materials throu h the tunnel, means for admitting heate fluids intothe tunnel at different points, outlets for the fluids, means forredirecting part of the outgoing fluids to the admitting means forrecirculation at successive oints in advance of the previous points ofadinission, and means for controlling said recirculation.

2i. A drying kiln for refractory materials, a tunnel, means for movingthe materials through the tunnel, means for admitting heated fluids intothe tunnel at different points, outlets for the fluids, means forredirecting part of the outgoing fluids to the admitting means lt'orArecirculation means for controlling said recirculation, and meanscooperating with the admitting means for supplying given amounts ofwater vapor.

22. A drying kiln for refractory materials, a tunnel, means for movingthe materials through the tunnel, means for admitting healed fluids intothe tunnel at different points, outlets for the fluids, means forredirecting part of the outgoing fluids to the admitting means forrecirculation, means for controlling said recirculation, and meanscooperating with the admitting means for supplying given amounts ofwater vapor.

and' means for var in the su l of va oi t'oh of said poiiitag pp y i p23,. A l'iln comprising a Vpassage for the movement of waretherethrough, admission chambers above and below said passage andhiiving ports of communication between said passa and said admissionchambers, a mixmg amber ,havingports of communication with saidadmission chambers,'bloweis in said mixing chamber and between itlieupper and lower ports of communication from said admission chambers,whereby circulation of the medium \in said chambers may be eil'ectedin avertical ldirection through said waremd. means foi,` conductin" atreatinv' m iuln into saidl in chimber. a I g 24. A kiln comprisingvapassage'- movement of Ware therethrou 11;;admissio` i chambers'above andbelow shi passage an havingports of communication between saidl passageand'said'gdmission chambers, aimixin g chamber having ports ofcommunication with said admission chambers, spra means located in saidmixing chambers an in said admission chambers at diilerent points -forthe distribution of moisture therein, and means for conducting a heatingmedium into said mixing chambers.

25. A kiln comprising a .passage for the movement of ware therethrough,admission chambers above and below said passage and having ports ofcommunication between said passage and said admission chambers, a mixingchamber having'ports of communication with said admissionchamber, heatinmeans extending' through said mixin vcham "rifr effecting radiant heatin`of t e mediumin the mixing chamber, an means for conducting a heatingmedium of one temperature into said mixing chamber and of ahigher;k

temperature into said heating ineens.

2Q. A kiln comprising a passage `for the movement of ware therethrough,admission chambers above and below said passageand having ports ofcommunication between said assage and said admission chambers, .a mixingchamber having ports of communication with said admission chambers, achecker work in said admission chambers for effect4 ing distribution ofthe heating medium, and means for conducting a heating medium into saidmixing chamber.

In witness whereof, w hereunto subscribe our names to thisspeciication.

l WILLIAM E. WILSON.

HENRY G. LYKKN ida 17. A kiln hai-'ing tunnels, means for movingrefractory materials alone,r said tunnels, ,eas inlets and ontiets insaid tunnels, means cmiii'oliing the flow of gas into the tunnels. meanslocated adjacent the inlei for supplyingr water vapor to the gasllowiupr imo said tunnels. and means for regulating the amount of watervapor Supplied at each of said inlet-.

18. A drying kiln for refractory materials. passages for the materials,means for movingv the materials through said passages, moans` for.circulatingY heated and humiditied fines through the imiterials in thepassages, and means for i'eciriiilating part of the circulated ,fraseswith the incoming gases at successivo points beyond the previous pointsot circulation of the gases.

I9. t drying: kiln for refractory materials. tunnels` means for movingthe materials through the tunnels. means for heating the materials chorethe boiling point of water, means for supplying at successive points in,said tunnel moisture to the exterior surface of the materials at a ratesubstantially equal to the rate ot' evaporation on the surface of thematerials.

Q0. A drying kiln for refractory matcrials, a tunnel, means for movingthe materials through the tunnel, means for admitting heated fluids intothe tunnel at different points, outlets for the fluids, means forredirecting part olf the outgoing fluids to the admitting means forrecirculation atV successive points in advance of the previous points ofadmission, and means for controlling said recirculation.

21. A dryingF kiln for refractory materials, a tunnel, means for movingthe materials through the tunnel, means for admitting heated 'iluidsinto the tunnel at different points, outlets for the iluids, means forredirecting part. ol' the outgoing fluids to the admittingil means `forArecirculation, means for conti-fillingslr said recirculation, and menuscooperating with the admitting means for .supplying given amounts of'Water vapor.

22. dryingY lriln for refractory materials. a tunnel, means for movingthe materials through the tunnel` means for admittin-g heated tliiilsinto the tunnel at ditferent. points` outlets for the fluids, means torredirectin; r part ot' the outgoing fluids to the admitting;y mean,s forincirculation, moans for controllingr said recirculation, and meanscooperating with the admitting means for supplying given amounts ot'water vapor,

and means for varying the supply of vapor at each of said points.

A i'iln comprising a passage for the movement of Ware therethrough,admission chambers above and below said passage and 'having ports ofcommunication between said 24. A kiln comprising a passage for the.

movement of ware therethrough,;admissio :hailnbers above and below saidpassage an having'ports of communication between said` passage and saidadmission chambers, a mixing chamber having ports of communication withsaid admission chambers, spray means located in said mixing chambers andin said admission chambers at different points -for the distribution ot'moisture therein, and means for conducting a heating medium into saidmixing chambers.

25. A kiln comprising a passage for the movement of ware therethrough,admission chambers above and below said passage and having ports ofcommunication between said passage and said admission chambers, a mixingchamber having ports of communication with said admission'chamber,heatin means extending through said mixing cham exi-,for

effecting radiant heatin of the medium'm the mixing chamber, an meansfor conducting a heating medium of one temperature into said mixingchamber and of alhigher temperature into said heating means.

26. A. kiln comprising a passage for the movement of ware therethrough,admission chambers above and below said passage and havingr ports ofcommunication between said passage and said admission chambers. a mixingchamber having ports ot communication with said admission chambers, achecker work in said admission chambers for effect-` ing,r distributionof the heating fnedium, and means for conducting a heating medium in/tosaid mixing chamber.

In witness whereof, we hereunto subscribe our names to thisspecification.

l WILLIAM E. W'ILSON.

HENRY, G. LYKKEN.

Cera 0f Correction.

It is hereby certified that in Letters Patent No. 1926, iliion theapplication of William E. Wilson, of G. Ly

1 57,Q59 granted Janus of Minneapolis, Minnesota, for an improvement in'Met ods of an Apparatus for Drying Refractory Materials# an errorrippears in the prints ifcatlon requiring correction as follows: Page 3,line V123, after the word insert the Word through.' and that the saidLetters Patent" should be read with this correction therein that thesame may conform to the record of the case in the Patent Ottico.

Signed and sealed this 23d day of March, it. D. 1926.

M. J. Moons, Acting Uomfmssz'oner of Patents.

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lir

Celiac Correction.

It is hereby certified that in Lochem Pant No. 1,579,659. gianted Janus.26, 1926, u on lche application of VVillinm E. Willson, of Mago Cty,Iowa, andV G. Lyen, of Minneapolis, Minnesota, for an improver'net in'Methods of atg Apparatus for Drying Refractory Ma'fals, an error zippeisin the prin s itcation requiringA correction as followsfPage 3, ln"128,.ater the word extend insert the word through: and thati the saidLetters Patent' Should be ead with this correction thQrein that the samemay conform to the record of the case in the Patent Signed and se'ledthis 23d day of March, A. D. 1926.

[snm] M. J. MQDRE,

Acting Commissioner of Patenti.

